Re: [PATCH 3/3] ntb_tool: Add memory window debug support

[Jon Mason]

On Fri, Jun 3, 2016 at 5:20 PM, Allen Hubbe <Allen.Hubbe@xxxxxxx> wrote:
> From: Logan Gunthorpe
>> We allocate some memory window buffers when the link comes up, then we
>> provide debugfs files to read/write each side of the link.
>>
>> This is useful for debugging the mapping when writing new drivers.
>>
>> Signed-off-by: Logan Gunthorpe <logang@xxxxxxxxxxxx>
>
> Thanks! This was on my wish list.
>
> Acked-by: Allen Hubbe <Allen.Hubbe@xxxxxxx>

Applied to my ntb-next branch

Thanks,
Jon

>> ---
>>  drivers/ntb/test/ntb_tool.c | 258 +++++++++++++++++++++++++++++++++++++++++++-
>>  1 file changed, 257 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/ntb/test/ntb_tool.c b/drivers/ntb/test/ntb_tool.c
>> index 209ef7c..4c01057 100644
>> --- a/drivers/ntb/test/ntb_tool.c
>> +++ b/drivers/ntb/test/ntb_tool.c
>> @@ -89,6 +89,7 @@
>>  #include <linux/dma-mapping.h>
>>  #include <linux/pci.h>
>>  #include <linux/slab.h>
>> +#include <linux/uaccess.h>
>>
>>  #include <linux/ntb.h>
>>
>> @@ -105,11 +106,29 @@ MODULE_VERSION(DRIVER_VERSION);
>>  MODULE_AUTHOR(DRIVER_AUTHOR);
>>  MODULE_DESCRIPTION(DRIVER_DESCRIPTION);
>>
>> +#define MAX_MWS 16
>> +
>> +static unsigned long mw_size = 16;
>> +module_param(mw_size, ulong, 0644);
>> +MODULE_PARM_DESC(mw_size, "size order [n^2] of the memory window for testing");
>> +
>>  static struct dentry *tool_dbgfs;
>>
>> +struct tool_mw {
>> +     resource_size_t size;
>> +     u8 __iomem *local;
>> +     u8 *peer;
>> +     dma_addr_t peer_dma;
>> +};
>> +
>>  struct tool_ctx {
>>       struct ntb_dev *ntb;
>>       struct dentry *dbgfs;
>> +     struct work_struct link_cleanup;
>> +     bool link_is_up;
>> +     struct delayed_work link_work;
>> +     int mw_count;
>> +     struct tool_mw mws[MAX_MWS];
>>  };
>>
>>  #define SPAD_FNAME_SIZE 0x10
>> @@ -124,6 +143,111 @@ struct tool_ctx {
>>               .write = __write,               \
>>       }
>>
>> +static int tool_setup_mw(struct tool_ctx *tc, int idx)
>> +{
>> +     int rc;
>> +     struct tool_mw *mw = &tc->mws[idx];
>> +     phys_addr_t base;
>> +     resource_size_t size, align, align_size;
>> +
>> +     if (mw->local)
>> +             return 0;
>> +
>> +     rc = ntb_mw_get_range(tc->ntb, idx, &base, &size, &align,
>> +                           &align_size);
>> +     if (rc)
>> +             return rc;
>> +
>> +     mw->size = min_t(resource_size_t, 1 << mw_size, size);
>> +     mw->size = round_up(mw->size, align);
>> +     mw->size = round_up(mw->size, align_size);
>> +
>> +     mw->local = ioremap_wc(base, size);
>> +     if (mw->local == NULL)
>> +             return -EFAULT;
>> +
>> +     mw->peer = dma_alloc_coherent(&tc->ntb->pdev->dev, mw->size,
>> +                                   &mw->peer_dma, GFP_KERNEL);
>> +
>> +     if (mw->peer == NULL)
>> +             return -ENOMEM;
>> +
>> +     rc = ntb_mw_set_trans(tc->ntb, idx, mw->peer_dma, mw->size);
>> +     if (rc)
>> +             return rc;
>> +
>> +     return 0;
>> +}
>> +
>> +static void tool_free_mws(struct tool_ctx *tc)
>> +{
>> +     int i;
>> +
>> +     for (i = 0; i < tc->mw_count; i++) {
>> +             if (tc->mws[i].peer) {
>> +                     ntb_mw_clear_trans(tc->ntb, i);
>> +                     dma_free_coherent(&tc->ntb->pdev->dev, tc->mws[i].size,
>> +                                       tc->mws[i].peer,
>> +                                       tc->mws[i].peer_dma);
>> +
>> +             }
>> +
>> +             tc->mws[i].peer = NULL;
>> +             tc->mws[i].peer_dma = 0;
>> +
>> +             if (tc->mws[i].local)
>> +                     iounmap(tc->mws[i].local);
>> +
>> +             tc->mws[i].local = NULL;
>> +     }
>> +
>> +     tc->mw_count = 0;
>> +}
>> +
>> +static int tool_setup_mws(struct tool_ctx *tc)
>> +{
>> +     int i;
>> +     int rc;
>> +
>> +     tc->mw_count = min(ntb_mw_count(tc->ntb), MAX_MWS);
>> +
>> +     for (i = 0; i < tc->mw_count; i++) {
>> +             rc = tool_setup_mw(tc, i);
>> +             if (rc)
>> +                     goto err_out;
>> +     }
>> +
>> +     return 0;
>> +
>> +err_out:
>> +     tool_free_mws(tc);
>> +     return rc;
>> +}
>> +
>> +static void tool_link_work(struct work_struct *work)
>> +{
>> +     int rc;
>> +     struct tool_ctx *tc = container_of(work, struct tool_ctx,
>> +                                        link_work.work);
>> +
>> +     tool_free_mws(tc);
>> +     rc = tool_setup_mws(tc);
>> +     if (rc)
>> +             dev_err(&tc->ntb->dev,
>> +                     "Error setting up memory windows: %d\n", rc);
>> +
>> +     tc->link_is_up = true;
>> +}
>> +
>> +static void tool_link_cleanup(struct work_struct *work)
>> +{
>> +     struct tool_ctx *tc = container_of(work, struct tool_ctx,
>> +                                        link_cleanup);
>> +
>> +     if (!tc->link_is_up)
>> +             cancel_delayed_work_sync(&tc->link_work);
>> +}
>> +
>>  static void tool_link_event(void *ctx)
>>  {
>>       struct tool_ctx *tc = ctx;
>> @@ -135,6 +259,11 @@ static void tool_link_event(void *ctx)
>>
>>       dev_dbg(&tc->ntb->dev, "link is %s speed %d width %d\n",
>>               up ? "up" : "down", speed, width);
>> +
>> +     if (up)
>> +             schedule_delayed_work(&tc->link_work, 2*HZ);
>> +     else
>> +             schedule_work(&tc->link_cleanup);
>>  }
>>
>>  static void tool_db_event(void *ctx, int vec)
>> @@ -443,8 +572,112 @@ static TOOL_FOPS_RDWR(tool_peer_spad_fops,
>>                     tool_peer_spad_read,
>>                     tool_peer_spad_write);
>>
>> +
>> +static ssize_t tool_mw_read(struct file *filep, char __user *ubuf,
>> +                         size_t size, loff_t *offp)
>> +{
>> +     struct tool_mw *mw = filep->private_data;
>> +     ssize_t rc;
>> +     loff_t pos = *offp;
>> +     void *buf;
>> +
>> +     if (mw->local == NULL)
>> +             return -EIO;
>> +     if (pos < 0)
>> +             return -EINVAL;
>> +     if (pos >= mw->size || !size)
>> +             return 0;
>> +     if (size > mw->size - pos)
>> +             size = mw->size - pos;
>> +
>> +     buf = kmalloc(size, GFP_KERNEL);
>> +     if (!buf)
>> +             return -ENOMEM;
>> +
>> +     memcpy_fromio(buf, mw->local + pos, size);
>> +     rc = copy_to_user(ubuf, buf, size);
>> +     if (rc == size) {
>> +             rc = -EFAULT;
>> +             goto err_free;
>> +     }
>> +
>> +     size -= rc;
>> +     *offp = pos + size;
>> +     rc = size;
>> +
>> +err_free:
>> +     kfree(buf);
>> +
>> +     return rc;
>> +}
>> +
>> +static ssize_t tool_mw_write(struct file *filep, const char __user *ubuf,
>> +                          size_t size, loff_t *offp)
>> +{
>> +     struct tool_mw *mw = filep->private_data;
>> +     ssize_t rc;
>> +     loff_t pos = *offp;
>> +     void *buf;
>> +
>> +     if (pos < 0)
>> +             return -EINVAL;
>> +     if (pos >= mw->size || !size)
>> +             return 0;
>> +     if (size > mw->size - pos)
>> +             size = mw->size - pos;
>> +
>> +     buf = kmalloc(size, GFP_KERNEL);
>> +     if (!buf)
>> +             return -ENOMEM;
>> +
>> +     rc = copy_from_user(buf, ubuf, size);
>> +     if (rc == size) {
>> +             rc = -EFAULT;
>> +             goto err_free;
>> +     }
>> +
>> +     size -= rc;
>> +     *offp = pos + size;
>> +     rc = size;
>> +
>> +     memcpy_toio(mw->local + pos, buf, size);
>> +
>> +err_free:
>> +     kfree(buf);
>> +
>> +     return rc;
>> +}
>> +
>> +static TOOL_FOPS_RDWR(tool_mw_fops,
>> +                   tool_mw_read,
>> +                   tool_mw_write);
>> +
>> +
>> +static ssize_t tool_peer_mw_read(struct file *filep, char __user *ubuf,
>> +                                size_t size, loff_t *offp)
>> +{
>> +     struct tool_mw *mw = filep->private_data;
>> +
>> +     return simple_read_from_buffer(ubuf, size, offp, mw->peer, mw->size);
>> +}
>> +
>> +static ssize_t tool_peer_mw_write(struct file *filep, const char __user *ubuf,
>> +                                 size_t size, loff_t *offp)
>> +{
>> +     struct tool_mw *mw = filep->private_data;
>> +
>> +     return simple_write_to_buffer(mw->peer, mw->size, offp, ubuf, size);
>> +}
>> +
>> +static TOOL_FOPS_RDWR(tool_peer_mw_fops,
>> +                   tool_peer_mw_read,
>> +                   tool_peer_mw_write);
>> +
>>  static void tool_setup_dbgfs(struct tool_ctx *tc)
>>  {
>> +     int mw_count;
>> +     int i;
>> +
>>       /* This modules is useless without dbgfs... */
>>       if (!tool_dbgfs) {
>>               tc->dbgfs = NULL;
>> @@ -473,6 +706,20 @@ static void tool_setup_dbgfs(struct tool_ctx *tc)
>>
>>       debugfs_create_file("peer_spad", S_IRUSR | S_IWUSR, tc->dbgfs,
>>                           tc, &tool_peer_spad_fops);
>> +
>> +     mw_count = min(ntb_mw_count(tc->ntb), MAX_MWS);
>> +     for (i = 0; i < mw_count; i++) {
>> +             char buf[30];
>> +
>> +             snprintf(buf, sizeof(buf), "mw%d", i);
>> +             debugfs_create_file(buf, S_IRUSR | S_IWUSR, tc->dbgfs,
>> +                                 &tc->mws[i], &tool_mw_fops);
>> +
>> +             snprintf(buf, sizeof(buf), "peer_mw%d", i);
>> +             debugfs_create_file(buf, S_IRUSR | S_IWUSR, tc->dbgfs,
>> +                                 &tc->mws[i], &tool_peer_mw_fops);
>> +
>> +     }
>>  }
>>
>>  static int tool_probe(struct ntb_client *self, struct ntb_dev *ntb)
>> @@ -486,13 +733,15 @@ static int tool_probe(struct ntb_client *self, struct ntb_dev *ntb)
>>       if (ntb_spad_is_unsafe(ntb))
>>               dev_dbg(&ntb->dev, "scratchpad is unsafe\n");
>>
>> -     tc = kmalloc(sizeof(*tc), GFP_KERNEL);
>> +     tc = kzalloc(sizeof(*tc), GFP_KERNEL);
>>       if (!tc) {
>>               rc = -ENOMEM;
>>               goto err_tc;
>>       }
>>
>>       tc->ntb = ntb;
>> +     INIT_DELAYED_WORK(&tc->link_work, tool_link_work);
>> +     INIT_WORK(&tc->link_cleanup, tool_link_cleanup);
>>
>>       tool_setup_dbgfs(tc);
>>
>> @@ -507,6 +756,8 @@ static int tool_probe(struct ntb_client *self, struct ntb_dev *ntb)
>>
>>  err_ctx:
>>       debugfs_remove_recursive(tc->dbgfs);
>> +     cancel_delayed_work_sync(&tc->link_work);
>> +     cancel_work_sync(&tc->link_cleanup);
>>       kfree(tc);
>>  err_tc:
>>       return rc;
>> @@ -516,6 +767,11 @@ static void tool_remove(struct ntb_client *self, struct ntb_dev *ntb)
>>  {
>>       struct tool_ctx *tc = ntb->ctx;
>>
>> +     cancel_delayed_work_sync(&tc->link_work);
>> +     cancel_work_sync(&tc->link_cleanup);
>> +
>> +     tool_free_mws(tc);
>> +
>>       ntb_clear_ctx(ntb);
>>       ntb_link_disable(ntb);
>>
>> --
>> 2.1.4
>
>